Coronaviruses and COVID-19

Learning Outcomes

Identify the origin and characteristics of SARS-CoV-2 and the disease it causes, COVID-19
Explain the concept of spillover and how it relates to the transmission of coronaviruses from animals to humans
List the symptoms of COVID-19 and differentiate between mild and severe cases
Describe the process of virus transmission and the factors that contribute to the spread of a pandemic

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Pneumonia

A disease commonly caused by bacteria that has entered the lungs. The affected person gets a high fever and a cough.

Symptom

A change in the body or mind, which indicates that a disease is present.

Epidemic

The rapid spread of a disease in a particular area or community.

Pandemic

The rapid spread of a disease in multiple countries or worldwide that affects a large number of people.

Coronaviruses

A large group of viruses that cause diseases in animals and humans. They are called “corona” because of crown-like spikes on the surface of the virus.

Incubation time

The period between being infected with a virus and the onset of symptoms.

SARS-CoV-2

A strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the COVID-19 pandemic.

COVID-19

A contagious disease caused by the virus SARS-CoV-2. The first known case was identified in Wuhan, China, in December 2019. The disease quickly spread worldwide, resulting in the COVID-19 pandemic.

On December 31, 2019, several cases of pneumonia are detected in the city of Wuhan, China. When doctors start to investigate why so many people got pneumonia at the same time, they find out that patients are infected with a new virus. Before it is discovered, the virus has spread to family members and healthcare workers. The disease spreads rapidly within China, and soon outside China when infected people travel. Researchers name the virus: SARS-CoV-2.

And the disease it causes: corona virus disease 2019. Or COVID-19. So far, we don’t know everything about this virus. But scientists all over the world are working hard to understand how it functions, and whether it’s possible to create a vaccine against it. Researchers have long known about the group of viruses that includes SARS-CoV-2.

Viruses in this group are round, and under a microscope seem to have crown-like spikes on their surface. The word for crown in Latin is corona, which is why we call this group of viruses: coronaviruses. The various types of coronavirus can cause various symptoms which might include: •coughing •breathing difficulties •tightness in the chest Referred to as Respiratory symptoms Or might include •diarrhea •nausea •vomiting Gastrointestinal symptoms But where do coronaviruses come from? The first time a coronavirus was discovered in humans was in the 1960s. It was discovered that humans could also be infected by a virus that previously had only been observed in chickens.

Since then, we know that coronaviruses can be found in several different animal species, including camels, civet cats, and bats. But sometimes a virus can make the jump to humans and infect them. This is called a spillover. It is not known exactly how SARS CoV 2 first infected humans. But scientists believe that the virus was most likely transmitted from animals, to a person who either had contact with, or had eaten an infected animal.

And many of the people who became ill in Wuhan had been to a food market where live animals and seafood were sold. Markets that typically have wildlife, livestock and humans in close proximity, exist all over the world. They are known by epidemiologists to be possible breeding grounds for epidemics and pandemics. We also know that the virus is transmitted from human to human, and that’s why it infects people in many places around the world. When a disease spreads widely in a population over a short time, the outbreak is said to be an epidemic.

An epidemic that affects very many people in many countries, is called a pandemic. On March 11, 2020, the World Health Organization, WHO, classified the spread of COVID-19 as a pandemic. Because COVID-19 is such a new disease, no one knows exactly how it spreads or how easily it spreads. If the virus has landed on a surface, and a person touches that surface and then touches their face, they can become infected. However scientists don't know for how long the virus stays on that surface.

They also do not know the exact time from being infected until you get symptoms - the incubation time. But it is believed that the incubation time for COVID-19 is five to six days, and a maximum of 14 days. So far, we know that COVID-19 can give both mild, and more severe symptoms. Mild symptoms: • Coughing • Fever • Shortness of breath Severe symptoms: •Pneumonia •Kidney failure In severe cases, it can cause death. Most of those who have been infected so far have had mild symptoms - similar to common flu.

One coughs, gets a fever, headache, and maybe pain in the body. But for older people, and people who already have a disease, COVID-19 can be dangerous, and even deadly. Many have already died. In order to reduce the risk of spreading the virus, it is important to be thorough about hygiene, to cough and sneeze into the elbow, and to wash hands thoroughly with soap. If you feel sick, have a runny nose, or cough, it is important to stay home from school or work, and not visit elderly or sick people.

Not even relatives. You may not be infected by COVID-19 if you cough - but it is unwise to take the risk! What we know about the COVID-19 virus can change quickly, because the virus is new and we learn more every day. A great place to get the latest information - is WHO's website! www.who.int